Instructions: *To prepare the cake:* 1. *Preheat*: Preheat your oven to 350°F (180°C). Grease two 9-inch (23cm) round cake pans and line the bottoms with parchment paper. 2. *Mix dry ingredients*: In a medium bowl, whisk together flour, sugar, baking powder, and salt. 3. *Mix wet ingredients*: In a large mixing bowl, beat the butter until creamy. Add eggs one at a time, beating well after each addition. Beat in vanilla extract. 4. *Combine wet and dry ingredients*: Gradually add the dry ingredients to the wet ingredients, alternating with milk, beginning and ending with dry ingredients. Beat just until combined. 5. *Divide batter*: Divide the batter evenly between the prepared pans. 6. *Bake*: Bake for 30-35 minutes or until a toothpick inserted in the center comes out clean. 7. *Cool*: Let the cakes cool in the pans for 10 minutes, then transfer them to a wire rack to cool completely.
*To prepare the vanilla buttercream frosting (optional):* 1. *Beat butter*: Beat the butter until creamy. 2. *Add confectioners' sugar*: Gradually add the confectioners' sugar, beating until smooth. 3. *Add vanilla extract*: Beat in the vanilla extract. 4. *Add milk*: Beat in the milk until the frosting reaches the desired consistency.
*To assemble the cake:* 1. *Place one cake layer*: Place one cake layer on a serving plate. 2. *Spread frosting*: Spread a layer of vanilla buttercream frosting on top of the cake layer. 3. *Place second cake layer*: Place the second cake layer on top of the frosting. 4. *Frost the top and sides*: Frost the top and sides of the cake with the remaining frosting.